Abstract

An essential protein of the SARS-CoV-2 virus, the envelope protein E, forms a homopentameric cation channel that is important for virus pathogenicity. Here we report a 2.1-Å structure and the drug-binding site of E’s transmembrane domain (ETM), determined using solid-state NMR spectroscopy. In lipid bilayers that mimic the endoplasmic reticulum-Golgi intermediate compartment (ERGIC) membrane, ETM forms a five-helix bundle surrounding a narrow pore. The protein deviates from the ideal α-helical geometry due to three phenylalanine residues, which stack within each helix and between helices. Together with valine and leucine interdigitation, these cause a dehydrated pore compared with the viroporins of influenza viruses and HIV. Hexamethylene amiloride binds the polar amino-terminal lumen, whereas acidic pH affects the carboxy-terminal conformation. Thus, the N- and C-terminal halves of this bipartite channel may interact with other viral and host proteins semi-independently. The structure sets the stage for designing E inhibitors as antiviral drugs.

View full article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7718435/

Mandala VS, McKay MJ, Shcherbakov AA, Dregni AJ, Kolocouris A, Hong M. Structure and drug binding of the SARS-CoV-2 envelope protein transmembrane domain in lipid bilayers. Nat Struct Mol Biol. 2020 Dec;27(12):1202-1208. doi: 10.1038/s41594-020-00536-8. Epub 2020 Nov 11. PMID: 33177698; PMCID: PMC7718435.